Urinary incontinence affects over 13 million men and women of all ages in the United States. Stress urinary incontinence (SUI) affects primarily women and is generally caused by two conditions, intrinsic sphincter deficiency (ISD) and hypermobility. These conditions may occur independently or in combination. In ISD, the urinary sphincter valve, located within the urethra, fails to close properly (coapt), causing urine to leak out of the urethra during stressful activity. Hypermobility is a condition in which the pelvic floor is distended, weakened, or damaged, causing the bladder neck and proximal urethra to rotate and descend in response to increases in intra-abdominal pressure (e.g., due to sneezing, coughing, straining, etc.). The result is that there is an insufficient response time to promote urethral closure and, consequently, urine leakage and/or flow results.
A popular treatment of SUI is the use of a sling, which is permanently placed under a patient's bladder neck or mid-urethra to provide a urethral platform. Placement of the sling limits the endopelvic fascia drop, while providing compression to the urethral sphincter to improve coaptation. Generally, the sling is surgically placed under urethra, close to the high-pressure zone with no elevation of the urethra. The ends of a sling may be secured to an anatomical location by, for example, a bone anchor. When abdominal pressure increases, the sling stops the descent of the urethra and functions as a mechanism of closure for the urethra to prevent urine leakage by maintaining its position relative to the anchored location. However, too much tension may be applied by this method, and the patient may go into retention, unable to void the bladder and suffer a pressure build-up in the bladder. Such pressure build-up can lead to reflux of urine up the ureters and into the kidney, eventually resulting in kidney damage, and, potentially, kidney loss. Clinically, there is technical challenge to positioning and applying the correct tension to the sling.
Additionally, conventional slings are typically formed from a woven fabric. The woven fabric can become twisted, stretched or otherwise permanently deformed during implantation, which can affect whether the sling operates correctly. To address this issue, conventional slings typically employ a protective sleeve to reduce the likelihood of the sling becoming deformed during implantation. A disadvantage of this configuration is that the sleeve ultimately needs to be removed from the patient's body.
Accordingly, there is a need for an improved surgically implantable sling-like support to which it is easier to apply a correct tension, and that does not easily permanently deform and/or require a protective covering.